Similar to creating a pattern from cloud formations, we look up to the sky and do the same for the stars. Officially, constellations are described as groups of stars that form human recognizable patterns. There are 88 patterns that have been formally recorded.
Historically, creating star patterns go back centuries. The term was first used in astrology and was derived from the Latin word constellātiō. The oldest recording of constellations began with the Middle Bronze Dynasties, around the years 2055 to 1650 BC. The Judah/Christian bible also has mention of star patterns in Job 9:9, 38:31-32, Hebrew “עיש `Ayish “bier”, כסילKĕciyl “fool” and כימה Kiymah “heap”, translated to be “Arcturus, Orion and Pleiades”.
There are 88 constellations, as listed in Wikipedia, with Orion being the most popular. The Orion Constellation represents the mythological Greek hunter. Some of the stars in the Orion Constellation are Betelgeuse ( 642.5 light years from Earth. Magnitude 0.45), Saiph (724 LY. MAG 2.07), Bellatrix (244.6 LY. MAG 1.64), Rigel (722.9 LY. MAG 0.18), Alnitak (826 LY.MAG 1.82) and Alnilam (1342 LY. MAG 1.69).
Additionally, the Orion Nebula, designated as M42, is also in this constellation. As with all nebula, it is beautifully colored and can be seen with the naked eye on a clear night. It is approximately 24 LY across and has a mass which is 2000 times the mass of our Sun. The Orion Nebula looks like a star without a telescope and is located within the constellation’s area of the hunter’s sword. Being so close, astronomers have a first hand look at how stars are born.
Another rather famous constellation is Ursa Major Latin for Great She Bear and more popularly known as The Big Dipper. Also known, in the UK as the Plough, it represents a group of seven stars called an asterism. They are the brightest stars in Ursa Major. One of the most famous of these stars is Polaris, also called The North Star. Polaris lies at the end of the handle of the Little Dipper (which is also part of Ursa Major). Looking through a telescope, you can find Ursa Major by drawing an imaginary line around its stars to form the Great Bear.